1. Field of the Invention
The present invention relates to a field service device and method for a vibratory flowmeter, and more particularly, to a field service device and method for facilitating a processing system replacement in a vibratory flowmeter.
2. Statement of the Problem
Vibrating conduit sensors, such as Coriolis mass flowmeters and vibrating densitometers, typically operate by detecting motion of a vibrating conduit that contains a flowing material. Properties associated with the material in the conduit, such as mass flow, density and the like, can be determined by processing measurement signals received from motion transducers associated with the conduit. The vibration modes of the vibrating material-filled system generally are affected by the combined mass, stiffness and damping characteristics of the containing conduit and the material contained therein.
A typical Coriolis mass flowmeter includes one or more conduits that are connected inline in a pipeline or other transport system and convey material, e.g., fluids, slurries, emulsions, and the like, in the system. Each conduit may be viewed as having a set of natural vibration modes, including for example, simple bending, torsional, radial, and coupled modes. In a typical Coriolis mass flow measurement application, a conduit is excited in one or more vibration modes as a material flows through the conduit, and motion of the conduit is measured at points spaced along the conduit. Excitation is typically provided by an actuator, e.g., an electromechanical device, such as a voice coil-type driver, that perturbs the conduit in a periodic fashion. Mass flow rate may be determined by measuring time delay or phase differences between motions at the transducer locations. Two such transducers (or pickoff sensors) are typically employed in order to measure a vibrational response of the flow conduit or conduits, and are typically located at positions upstream and downstream of the actuator. The two pickoff sensors are connected to electronic instrumentation. The instrumentation receives signals from the two pickoff sensors and processes the signals in order to derive a mass flow rate measurement, among other things. Vibratory flowmeters, including Coriolis mass flowmeters and densitometers, therefore employ one or more flow tubes that are vibrated in order to measure a fluid.
During operation, the meter electronics of a vibratory flowmeter may acquire unique and useful data. The data may include configuration data that configures the vibratory flowmeter. The data may include calibration data that calibrates measurement values produced by the vibratory flowmeter. The data may include meter verification data that verifies proper operation of the vibratory flowmeter.
This data is important for proper operation of the flowmeter. This data may include data that reflects a current operational state of the vibratory flowmeter, wherein the data may include information regarding changes to the vibratory flowmeter over time. Changes in the vibrational characteristics may be due to use, corrosion, erosion, and/or other factors, for example. These changes to the flowmeter may be captured in the data.
A problem occurs when a processing system of the vibratory flowmeter needs to be replaced. The processing system may need to be replaced even where only partial failure has occurred. It should be understood that the failure may not necessarily affect a memory that stores this data.
Replacement of the processing system causes difficulties. Replacement of the processing system may result in post-replacement operational data, generated after installation of a replacement processing system, being scaled differently from the pre-replacement operational data due to gain differences through the electronics. Comparing the new operational data to the pre-replacement operational data may improperly indicate failures in the meter due to this scaling difference. As a result, the processing system replacement may be problematic and difficult.
Currently, if an enhanced core processor fails, the factory baseline must be reestablished by a field service person. The field service person must run the same algorithm as would be done in the factory in order to reestablish a new factory baseline. This process can be problematic due to customer timing, personnel availability, et cetera. A root cause for needing to reestablish the baseline with a new core is due to the fact that the electronics vary due to component tolerances. The component tolerances may be much greater than the necessary precision of the meter verification results.